Hacksaw-machine.



j. W. BOYNTON.

HACKSAW MACHINE. APPLlcAloN FILED 1AN.21.19716.

v Patentd Jan. Y, 1919.

T SHEETS-SHEET `I 1. w. BOYNTON,

HACKSAW MACHINEx APPLICATION FILED IAN.27, I9I6.

Patented Jan. 7, 1919.

TSHEETS-SHLLI 2 1. w. oYmoN.

l HACKSAW MACHINE.' APPmcATloN FILED 1AN.27,191.

LQQOAQT; K lemme@ Jan. 7,1919

TSHEETS-SHEET 3A I. w. o'YNToN. HACKSAW MACHINE.

APPLICATION FILED JAN.2T. ISIS.

Patented Jan. 7,1919.

7 SHEETS-SHEEI 4.

L w. oYNToN.

HACKSAW MACHINE,

APPLICATION FILED mm2?. 191s.

1 290 497. Patented Jan. 7,1919.

rsHEET'ssHEEr 5.

//V Vf /V 70A JOHN VM 50m/70N A7 of? fr J. W. BOYNUON. HACKSAW MACHINE. APPLICATION FILED IAII.21. I9I6.

IIII

Patented Jan. 7,1919.

7 SHEETS-SHEET 6X I| Imm' i'uu'bmf I. w. BOYNTUN. HACKSAW IVIACHINEE APPLICATION FILED .IAN.27. |916.

Patented Jan. 7, 1919 SHEETS-SHEET 7.

.UNITED strains PATENT JOHN W. BQYNTON, OF ATHOL, MASSACHUSETTS, ASSIGNOR TO THE L. S. STARRETT COMPANY, OF ATHOL, MASSACHUSETTS, A CORPORATION OF MASSACHUSETTS.

HACKSAW-MACHINE.

Application tiled January 27, 1916,

To all 107mmy t may concern.'

Beit known that I, JOHN W. BorN'roN, a citizen of the United States, residing at Athol, county ot lVorcester,Commonwealth of ll/Iassachusetts, have invented certain new and useful Improvements in Hacksaw- Machines, et which the following is a speci-I ication.

This invention relates to hack saw machines and particularly to a power hack saw machine.

In such machines the saw frame is usually weighted to hold the saw to the work during the cutting stroke thereof. The delicate nature of the saw blade itself and the rapidity at which these machines operate require special refinements in the feed mechanism, since any excessive shock to the teeth in urging the saw to the work or in moving the saw through its return or non-cutting stroke is liable to seriously injure the teeth. There the saw has simply been dragged across the work on its return stroke, the teeth have been particularly liable to injury. It has therefore been proposed to positively elevate the saw on its return stroke, thereby clearing the teeth from the work. Experience has shown, however, that where the saw is j positively raised at the completion of its eutting stroke, it is practically impossible to quickly replace the saw in contact to begin a new cutting' stroke without excessive shock to the teeth, due to the lowering of the saw from its elevated position to its position in the saw cut, and this is especially so where the saw is lifted a substantial distance from the work at the end of its cutting stroke. Moreover7 in such lowering there is a noticeable tendency on the part of the teeth to catch the sides of the saw eut.

Furthermore the rapid raising of the weighted saw has a most destructive effect on the ratchet teeth or other mechanism employed in making the lift.

The present invention contemplates a power hack saw machine wherein the saw is automatically returned to position to begin a new cutting stroke without lifting the saw from the saw cut. Accordingr to the present invention, von the return stroke of the saw the teeth travel backwardly in substantially the same path in which they advanced during` the cutting stroke. This is effected by a grip and release mechanism which al.

ternately interrupts and releases the nor- Patented dan. 7, i919.

serial No. 74,580.

mal gravity weights. This mechanism is actuated automatically from the power shaft of the Inaehineand acts to positively grip the saw at the completion of a cuttingstroke se as to lock it during the return stroke, and to au-v tomatically release the s aw at substantially the moment it is in position to begin a new cutting stroke. The tendency of the saw when released to drop onto the work, with resultant injury to the teeth, is therefore eliminated, and the saw cut is correspondingly protected from abrasion.

The saw blade is held at a slight angle to the carrier slide, so that it clears Very slightly on the back stroke, thus further relieving the teeth from wear due to contact with the bottom of the cut when being returned to position to begin its cutting stroke.

ln addition to the above indicated felatures, the present invention embodies a novel mechanism for adjusting the stroke of the saw according to the size of material to be cut, allowing the full length lof the saw to be utilized on all sizes of material within the range oi the mechanism. This stroke adjusting mechanism has a definite relation to the work clamp itself so that as' soon as this clamp is adjusted the stroke of the saw may be quickly and accurately regulated in accordance therewith.

These and various other features which will appear more fully hereinafter are secured in the machine of the present invention, the construction and operation of which is disclosed in the accompanying specification and drawings in which like reference characters are correspondingly applied throughout.

Figure l is an elevation, partly in section of a power hack saw machine in accordance with my present invention and showing the position oi the parts after the saw has cut.

Fig. Q is an elevationview from the opposite side.

Fig. 8 is a detail section on the line3-3 of Fig. l.

Fig. 4 is a view similar to Fig. l and showing the position of the parts at the beginning of the cutting` operation.

Fig. 5 is a detail view of one of the members et the gripping mechanism for auto matically relieving the saw of the feed pres-v sure.

Fig. 6 is a detail View of the releasing cam tendency of the feed pressurel fLD 8 is an enlarged View, partly in section, of the head of the machine and partieularly illustrating the relation ot' the gripping mechanism to the rest of the machine.

9 is aplan View of the machine.

Fig. l is atransverse section across the machine at the power s1' ift end thereof, and

'il is a detail vidio' at right angles to Fig. 10 and viewed from the left of said figure.

lf have indicated at l a suitable supporting' pedestal baring a vflat top 2 to which is bolted or ptlierwise secured a bed, plate 3. he work elanip for hc work "W consists of a fired jaw 4 and a movable jaw The movable jaw 5 is guided` in suitable ways (l formed on. the bed plate, and is advanced toward and from the iixcd jaw 4 by a feed ,screw 7 journaled in suitable bearings 8 on me bed 3 and provided beyond the end of the machine with an operating handle 9.

The plate 3 is provided adjacent. the work clamp w'th a series of ini-flicatlons 1G (see. 9) whereby the degree oi separation of the jaws 4 and 5may accurately determined and the length of the power stroke of the machine be adjusted inuaccordance therewith as will be more 'tally plained hereinafter. in the embodiment shown, these indications 10 consist of the numerals l, 2, 3, 4, 5, and G.

The numeral 11 indicates a. vertically movable reciprocating saw frame. 'ihe opposite ends of the franiell formed as bearings lil in which are n'iounted stems 12 to which a saw blade 13 is detachably connected and set at. a slight angle to the frame back for clearance. v y

ribe blade adapted to be strained to sion by any suitable tension device as 'the ision lever ifi'. rThe lever i4 is pivoted ends vl5 in suitable l,ars 1G profling .trein one arm of the i'rainc ll. 'lie "ee end oi" said lever plays between ille bearing 3.11 for one oi' the stems l2 and a pin i? on said slain. lthe opposite end of lever lli is suitably formed lo receive a thrsaided siem i8 working, in a bearing; l) in the saw frame ll. The siem lo and convjlently the lever 14 is adjusted by any suitable device as the hand wheel 20, thereby applying;` tension to the saw or relieving the saw of the tension.

The saw frame 11 is mounted in vertically swinfrable relation to the power shaft 2H of the machine and swings about Said shaft as a pivot. The structure for so mounting said traine consists of a horizontally disposed pivot arm 25,11aving a downwardly extending forked end 26. The forks 26 are formed as annular bearings through which a bushing 27 about the power shaft 28 is inserted and secured. From the forks 26 the arm extends upwardly and horizontally, and terminates in a tapered rib 23 which is cast on a horizontally disposed guide portion 21 for the saw frame. The lguide 21 and arm 25 are therefore cast in one piece. The connectingr arm of the saw frame is channeled in cross section (see Fig. 3) and in order to cause the traine to substantially wholly embrace the guide portion 2l, two spaced strips 22 are secured by screws` or equivalent fastenings 221 to opposite edges of one face of said connecting); arm, as clearly .shown in Fig. 3.

forks 26 of the arm 25 are provided with suitable oil cups 2G1 and the sleeve or bushing,f is suitably bored, as indicated at 262 (Fig. 10) whereby lubricant may be introduced to the power shaft. rlfhe bushing; 27 itself is set in a suitable loesiriinar 40 rising from the bed plate 3. The bushing 27 is held against rotation by a screw passino 'through the slotted housing, which housing' is an integral part of the bed. The bearing 40 has an oil cup 4l, andthe bushing is circumferentially groored as indicated at 42 and bored at 43 adjacent. said cup in order to permit lubricant introduced through the cup 41 to reach the power shaft.

rihe arm 25 and therefore the saw frame is swung about the power shaft as a pivot.

)Feed pressure may be applied to the saw frame in any suitable manner, as by weights or spring. I prefer to apply this pressure by weight, and for this purpose the arm 25 has a bearing' 35 rising; therefrom through which a weight carrying arm 36 is adjustably mounted. The adjustment of the arm 3G is held by a set screw or equivalent device 37, in said bearing. The weights 38 are in turn adjustable along' the arm 3G and their adjustment is held by the lscrcwlevers 39.

The saw frame is reciprocated from the power shaft by any suitable inotion conyertinpr mechanism which transmits the rotation of the power shaft reciprocatory mol ion applied to the said frame. Loose on the power shaft, near one end thereof, is a pulley 44, belted to a suitable source of power and designed to be alternately clutched to and released from said shaft by an automatic clutch mechanism described hereinafter. Fast on` said shaft near the opposite end therof is a crank arm 45 carrying a slide element 46 Working in a slot 47 in one arm 48 of a triangular lever 49 pivoted at 50 to the bed plate 3. The lever 49 has a quadrant. portion 51 provided with a slot 52 inwhich works a slide element 53 on a pitman 54, the opposite end of which is jtastened at to one arm of the saw frame 1l. v

The rotation ot' the power shaft is therefore eornerted into reciproeatory.motion 'by the cranlY -fl-j to swing the lever 49 on its pivot 5t). niitted to the saw frame as reciprocatoly motion by the pitn'ian to move the saiv back and torth across the work lll held in the clamp 4 5.

The elieective thron or stroke et the pitnian and thus the saw trame is adjusted by manually varying ther position oil the slide element in the' slotI of the quadrant arm 5l 'of the lover 49 and this adjustment is held by means of the shiftable locking device 5G. rllhis changes the effective available length of the slot 52 in which the slide 53 may play and therefore Yaries the effective lever arm of the pitinan.

In order that the degree of adjustment may be accurately detern'iined, the quadrant 5l adjacent the slot 52 is provided with a series ot indications 57 (see Fig. 2) whereby the exaet positioning` ot the slide then-'1in may be known. These graduations 57 are related to the graduations l() adja-V cent the ivork clamp so that both the degree or" separation ol the jaws [1-5 and the stroke oi" the piiman may be correspondingly adjusted according to the dimension and character ot the work being out.

lu the present invention, means are pro vided 'For relieving the saw :traino oi' the ifeed pressure in the return or non-cutting stroke ot the saw without lifting the .saw trame whereby the teeth oi the saiv blade are moved l'nwkvfardly in substantially the same` path in which they advanced during the cuttingstroke. and are again moved into the work gently and without undue `shook as soon as the saw reaches a position in ivhiffh Vto begin a new cutting stroke. Such pressure relieving means consists broadly o" an automatically operative gripping nieehanism designed to interniittently engage and release a part ot the saw frame ivhrrelrv to alternately interrupt and release the downward gravity tendency oi the toed pressure nf'eights 39 and an actuating` mechanism driven trom the power shalt and designed to be alternately actin att-d and released by a 'cam on said shaft awarding to the relation oi the saine frame to its cutting or non-eutting stroke.

'this pressure relieving mechanism more speeilieaily consists ot a curved arm 58 pivoted to the guide member 2l at and depending loosely therefrom. This arm is adapted to be alternately gripped and' released according to Whether the saw is on its cutting or non-cutting stroke by a spring tensioned plunger 60 having a'cylindrieal `head (il.

The end of the plunger 6G, exnosed to the arm 58, is formed a hear- This swinging motion is transing tace rounded circuni'ferentially (to conform to the arm 58) but fiat in the direction of its vWidth, e., transversely of the Inachine, so as to provide the same bearing to the arm at all points across Said efxposed face. The plunger G0 is reciprocally mounted in the chambered end 62 of a cam actuated lever 63 pivoted at one end at 64 to a casting 1GO rising from the bed 3, and having a roll 65 at its other end disposed for alternate actuation and release by a cam GG fast on. the crank 45. Confined Within the chamber 62 between the rear wall thereof and the head (Sl of the plunger" is a coil spring 67,` 'the normal tendency of which is to maintain the head G1 in gripping contactwith the arm 58. Beyond said rear wall the plunger stem is threaded as indicated at (38 to receive one or more check nuts (if) adapted to set up against said rear Wall to hold theI adjustment of the plunger. The head of the plunger has a longitudinal rhannel 70 (see Fig. 8) coperating with a suitable set screw 71 through the chamber G2 to guide the plunger in its reciprocations and to prevent the plunger turning in the rhamber under the action of the spring 67.

T he plunger head is normally engaged with .the curved arm by the action of the spring G7. llVhen the machine is started, it is necessary to release this engagement in order topermit the saw to descend into the work on the cutting stroke thereof. This release effected 'manually through a' link release pin 72 rotatably mounted n a bearing 73 formed on a lateral extension 161 oif the casting 160. The pin 72 has a dat 74 brtnf'cen its ends against which a release stud 75 is adapted to bear. The stud 75 is guided in a boss 7G formed on the bearing 73. Beyond the bearing 75l the pin 72 is provided with an operating handle 77 whereby the pin may be rotated 1nan' ually. Surh rotation causes the pin through its flat 7l to move the stud 75 against the head ot thel plunger (30 overcoming the spring 67 and causing the head to release the link 58. As soon as the stud 75 is released7 that is', as soon as the saw begins its cutting stroke, the pressure on the spring 67 is removed to'position to again grip the link 58. This grip does not occur houf'ever until the cam 66 has made a half revolution thereby bringing its dwell-Z against the ram roll oi" the level' ($3 and moving said lever toward the arm whereby to positively grip it on tho return or non-cutting stroke ot' the saw.

I) ot the eam extends 'haiic Way around the perii'ihery of the ram. The low part of the cam isindicated by the reference character a.. The cam roll 65 is there` fore engaged by the dwell o during one halt the revolution oi the cam and the cam is so set on the power shaft that this enand the plunger is returnedgageinent occurs during the return stroke of the saw. v.

It will therefore he evident that the arm 58 is alternately released and gripped on the cutting and non-cutting strokesrespecn i tively of the saw, through the action of the ,I This alternately applies and re#y The power is automatically applied and thrown out at or near the end of each stroke l) f' a clutch mechanism coni irisinca ivoted lever i8 adapted to oe initially actuated by a manually operable starting handle 80 which is set through the end of the lever 78 and held thereon by a squared nut 79. rlhc lever 78 is pivoted between its ends at 8l to the bed plate and beyond said pivotl is curved upwardly as indicated at 781 and best shown in Fig. 8. Fastened to this curved end is an actuating dog- 82 disposed for tripping engagement with one end 83 of a double ended pawl 84 pivotally mounted at 85y on av pawl disk 8G pinned on the power shaft by the pin 87 (see Fig. lil). The other end 88 of tne pawl 8s is disposed for engagement in the notch 89 of a ratchet disk 90 carried by the hub of 'the driving pulley 44 (Fig. 8). The end 88 of the pawl is normally held in engagement with the notch 89 by a blade springr 91 fastened to the pawl disk 86 with its lliree end bearing against the under face of the pawl.

Spring tension is applied to the starting lever 78 by a spring backed pin. 92 mounted in a socket in the bed plate, see Fig. 8) and engaging' a shoulder 21 on said lever beyond its pivot 8l. llien the saw has cut entirely through the work and the starting lever is released by a trip device hereinafter described, this pin 92 serves to throw the curved end 781 of lthe lever 78 into the path of the paw] 8l: so that when the rotation of the pawl disk 88 brings the pawl around, its end 83 will engage the dog 82, thereby rocking the paiwl on its pivot and throwing its end 88 out of the notch 89 of the .disk 9G to disconnect the power.

The pawl disk 86 is provided on its opposite face with a double ended stop 94. which defines with the disk 86 a curved recess 941 in which a dog 95 (see Fig. ll.) on the opposite face of the starting lever 78 is disposed. This device constitutes an emergency stop and its action is follows. In the event that after the pawl 8st has been positively disengaged from the notch of the disk 90 by the dog 82, the power pulley le should for any reason stick on the shaft 28 Aand therefore tend to rotate said shaft with re sultant damage to the saw teeth, 'the emergineens? ency stop 94:-95 will operate to positively lock the shaft against rotation. The action or' this stop would be to bring one of the two ends of the member into Contact with the dog 95 on the. lever 78 'thereby positively preventing further rotation of the power shaft.

and associated parts, the starting handle 8() is initial-ly lifted to engage it with a pivoted latch 97 {see Fig. d). rl`his swings the lever 78 on its pivot, causing the dog 82 to swing down away ironi the end 88 of the-paiwl 84e. llie spring 9i, then forces the end 88 of the pawl into the notch 89 ot the ratchet disk 99. This couples the paal disk 86 to ratchet dislr 90, which rotates with continuously running loose pulley 44;, and since the disk 86 is fast on the power shaft 28, said shaft is revolved.

During the cutting action of the machine, the dog 82 o'f the lever 7 8 is normally positioned, out of the path of the pawl Si on the ln the operation of the clutch mechanism disk 86,' Fig. d) and the stop on said disk simply rotates freely without effect on the dog 95 et said leven llhen, however, the has cut entirely through the work, the starting lever is automatically released by a release mechanism hereinafter described landthe curved end 78l 0r" said lever is moved by the spring pin 92 into the path of the rotating disk 86. This brines the dog 82 in position to be engaged by the end 83 of they pawl 84 and said engagement rocks the pawl on its pivot 85, tipping the end 88 thereof out of the notch 89 on the ratchet disk 90. if for any reason this fails to disconnect the power, the continued rotatioiifot the pawl disk brings one of the ends nf the double ended stop 94e into contact with the dogl 95 on the opposite face oi, the starting lever 78 thereby positively checking the rotation oit said disk and throivinff out the power,

The mechanism for automatically disconnecting the clutch when the saw has continued entirely through the work consists of a right angled trip lever 9G carried by the saw traine and a latch 97 pivoted at 98 to the casting 160 and having a hooked end 99 disposed for latchingengageinent with the starting; lever 78. rlhe clutch is backed at this end by a blade spring 100 fastened to the latch and playing` against a pin 101 on the casting 160. The normal tendency. ofi the spring 100 is to maintain the hooked end of the latch in position to be engaged by the squared nut 79 on the starting handle 80, when said handle is lifted to engaging position in starting the machine.

The other end 102 of the latch is disposed horizontally at substantially right angles to the portion 99 so as to project in the path of the trip lever 96. When the saw cuts entirely through the work, the frame has reed/ier lowered suliiciently to permit the trip 96 to strike the arm 102 ot the latch7 moving' the opposite end @thereof backwardly against the spring lOOfand ont of engagement with the starting lever which is consequently released and through the mechanism bet'ore` described disconnects the power.

ln the present machine a lubricant is supplied to the iwork in `any desired n'ranner7 as by means et a pump P secured to the frame at any convenient place and a connection 120 to the work. The pump P is provided with'a pulley 121 which is adapted to be belted to a pulley 122 tast on the drive shaft of the machine. The arrangement is such therefore that the pump is driven and lubricant supplied only while the machine is in operation, thereby effecting a saving in the lubricant used.

Any suitable work gage, as the gage, 123, may be mounted adjacent the work clamping jaws 4 and 5.

The complete operation of the machine is Y as follows:

The handle 77 of the pinch pin 72 is .first manually operated to release the pivot arm 58 and permit the saw to be raised.

. The arm 25 is raised, and with it tln` saw and weights, to the position shown in Fig. 5. The work is then inserted between the clamping jaws 4 and 5, and these jaws properly adjusted. At this time the throw of the pitman 54 may be adjusted by means let the hand device 56 as before described? and the extent of this adjustment with relation to the adjustment of the work clamping jaws may be accurately determined by means of the respective series of related graduatin-ns ot these parts. The operative next lifts the starting handle 80, to cause the squared nut 79 thereof to engage the hooked end 99 of the latch 97. This movement et the starting` lever carries the dos; 82 thereof away from the exposed end S3 of the double ended pawl 84:, permitting the spring' 91 for said paw] to move its other 'end SS against the periphery ot the notched disk D() in position to snap into the notch 89 thereof when the pawl begins to revolve. inasmuch as the pulley lit is constantly revolving, and until the clutch is thrown in, revolves a loose pulley, the disk 90 acts to connect the power to the shaft when the clutch is thrown in.

When the clutch is thrown in, the crank arm 45 begins to revolve swinging' the trim angulall plate 49 about its pivot 50 and causingr the pitlnan 54 to draw the saw rearwardly and downwardly, which direction is the cutting* stroke oi the saw. During the cutting stroke of the saw the vcam roll 65 ot' the lever (3S- is engaged by the low part f/ ot the earn 66 on the drive shaft and the curved arm 58 ot the saw frame 1s therefore -iraine and the leed plate not gripped by the plunger carried by said lever G3 so that the saw may descend to the work and make a out. rl/'hen the saw reaches the end of its cutting stroke, the high part or dwell 71 of the cam (iti engages the cam roll G5 ot the roll 63 cansinfr said lever through its plunger 68 to positively grip the arm 58 thereby locking the saw frame in this position. The continued rotation of the shaft 28 swings the saw frame ack to position to start a new cutting stroke and during this return ot the saw trame the high part of the cam 66 maintains the grip of the plunger 68 on the curved arm 58. The saw trame is therefore moved on its return stroke without liftinel the saw from its kerf and without liability of the teeth. marringr the sides of the saw out, or being injured by droppingv into the kerf when the teed pressure is released. Vhen thevsaw frame reaches the end of its return stroke, the high part of the cam 66 has ro; tated past the cam roll 65. The roll 63 is therefore released, and a conseduent re' lease of the curved arm 58 is cii'ccted, so that the saw may descend to the work under the pressure exerted by the feed weights, 38. This action is automatically repeated until the work is eut through.

When the saw cuts through the work the trip lever 96 on 'the saw 'fr'ame strikes the horizontal arm of the latch 97, tipping said arm downwardly. and causing' the hooked end of said. latch to release the starting lever. The starting; lever .78. being thus refleased, is acted upon by the spring' pressed pin 92 to cause its dop; 82 to move into the path ot the pawl 94 on the disk 86, and

said pawl is tripped out. ot' the notch S9 oi" to settle in'to the 'cut gently and without shock so that it. will be floated as it were, during" its cutting,` action, i interpose be' tween the pivoted arm 25 carrying the saw 3, a suitable motion checking device which in the embodiment shown, is in the form of an oil piston. s shown in Fig. 8 most clearly, I provide a cylinder '108 formed at its lower end to receive a fasteningy 107 which connects this end ot the cylinder to bed 3 ot' the machine.l This cylinder is adapted tojbe filled with any proper fluid such as a heavy oil, and is provided with a suitable closure at its upper end. The piston stem 1l() is pivoted at its upper end at-lO to the saw frame -said stem. Bearing against the lower edge of the hub 117, and confined between. it and the head of a screw 118, set in thelower end of the stem 110 is a coil spring 119, the normal tendency of which is to maintain the members 114 and 116 in sealing relation.

1n my construction, tbe operator is re lieved of the necessityr of manually raising the saw frame and ot holding it in a raised position While inserting new work into the work clamp, thus leaving his hands free to properly adjust the work. The saw frame is aised by the' weight ot, the open' ator applied to a treadle 29 pivoted near the base of the machine frame and operatively connected to the saw frame supporting arm 25 by a link 33. if] hen elevated to its raised position by said treadle, the saw frame is supported by the oil piston. in the operation of the treadle, the raising oi.1 the arm :25 lifts the stem 110 from the position shown in Fig. 1, tothe position shown in Fig. 1, against the pressure of the fluid as it passes through the openings 115. This pressure is sui'liciently great to counteract thetendency ot the spring 119, to maintain the members 114 and 116 in sealed relation, and therefore permits the separation of said members and a consequent passage of the tluid through the openings 115 from above the pist-on to the side below. This action is entirely automaticI and. the dash pot therefore, not only permits the saw to float down into the eut at each rapid release of the saw by the gripping de vice, but also assists to check Vibration, and tends to keep the saw bladesteady in the korf during the cutting action.

From the foregoing therefore it will be seen that thc action of the machine alter starting is to intermittently interrupt and release the downward gravity 'tendency of the ieed pressure weights to urge theA saw into the work, and that when this tendency is interrupted by the grip and release inochanisrn, the saw is locked at the completion ot its cutting stroke and is returned to position to begin a new euttingstroke 'without lifting and in substantially the path trayersed during the cutting strolre. itt will further be noted that in the present invention, feed pressure is exerted by the Leanne? weights 38 and no additional counterbalancing the frame i uired. The saw itself is permitted to tie down into the cut, atterrit has been can ried. back to position to begin a new cutting stroke and released by theinterinittent gip action which is to permit the saw to descend to the work gently and without shock under the downward tendency of the feed pressure weights. The action or" the machine is there`= Yt'ore smooth and practically without shock.

The 'feature of floating the saw trame on the piston or an oil filled cylinder resistant to the downward gravity feed but non re .sistai1t to the'uplit't of the saw trame and the treadle lift therefor are merely illustrated herein as showing my machine in its commercial form, but are not my invention and are not claimed herein.

. Various modifications in the construction and operation oi my machine may obviously 'be resorted to without departing from the spirit oi my invention if Within the limit of the appended claims.

'llllhat l therefore claim and desire to secure by Letters Patent is:

1. ln a cutting machine, in combination, a. cutting element, means ior exerting feed pressure upon said cutting element, means tor gripping the cutting element to relieve the feed pressure thereon at the completion at a cutting stroke, means effective when the cutting element is gripped to return said element to position to begin a new cutting stroke without lifting said element from the' cut previo'. il made, and means whereby said gripping: means is automatically released on the operative stroke or" the cutting element.

2. 1n a cutting machine, in combination, a cutting element, means for exerting leed pressure upon said cutting element, means for automatically gripping the cutting element to relieve the tend pressure 'thereon at the completion of a cutting stroke, means effective when `the cutting element is gripped to return said elenientto position to begin a new cutting stroke without liftingl said element troni the cut previously made, anal means whereby said gripping ineens is aultomatically released on the operative stroke ott the'cutting element.

3. ln a cutting machine, in combination, a cutting element, means for normally exerting feed pressure on said element Uhring the cutting stroke thereof, means for gripping said element to prevent the feed thereof on 'the non-cutting stroke, means eiiective when the cutting element is gripped to re turn said cutting element to position to begin a new Jutting stroke without lifting said element iroinlthe out previously made and in substantially the line traversed on the cutting stroke, and means whereby said gripping means is automatically released on the operative stroke oi the machine.

4. In a cutting machine, a cutting element, means for normally Vexerting feed pressure thereon during its cutting stroke, a member carried by said cutting element, means for gripping said member to prevent feed of the cutting element on the non-cutting stroke, and means eiiiective when said member is gripped to return the Ycutting elementto position to begin a new cutting stroke without being lifted from the cut previously made and in substantially the line traversed on the cutting stroke.

5. In a cutting machine, a. cutting element, vmeans for normally exerting feed pressure on said cutting element, automatic means for alternately gripping and releasing said cutting element to prevent and permit the feed thereof according to the position of the cutting element, and means effective when the cutting element is gripped to return said element to position to begin a new cutting stroke without being lifted from the cut previously made and in subf stantially the line traversed on the cutting stroke.

6. In a cutting machine, a cutting element, means for locking said element to prevent feed thereof at the end of its operative stroke, means effective when the cutting element is locked to return said element to position to begin a new cutting stroke without lifting said element from the cut previously made and in susbtantially the line traversed on the cutting stroke, and means whereby said locking means is released on the operative stroke of the cutting element.-

7. In acutting machine, in combination, a cutting element and a power shaft, means actuated from said power shaft for automatically locking said element to prevent feed thereof at the end of its operative stroke, means effective when said cutting element is locked to return said cutting element to position to begin a' new cutting stroke without lifting said element from the out previously made and in substantially the line traversed on the' cutting stroke, and means whereby saidlocking means is automatically released on the operative stroke of the cutting element. y

8. In a cutting machine, in combination, a cutting element and a power shaft. feed meansfor said cutting element, an'auto matic device' for alternately gripping. and releasing, said cutting element actuated by said shaft, and adapted to alternately pre'- vent and permit the feed oi the cutting element, and means effective when said cutting element is gripped to return said element' to position'to begin newA cutting stroke without being liited made.

0. In a cutting machine, a power sliait, a cutting element, feed moans sait.. cutl'ing element, a member carried by said element, an automatic device 'for alteri'iately gripping and releasing said member actriated from said shait and adapted to alten nately prevent and permit the .toed of the cutting element, according to the position of said element, and means effective when 'i from the out previousiy said member is gripped to return said cutting element to position to begin a new cut.- ting stroke without being lifted from the cut previously made.

adapted to positively grip the saiv at the i end of cutting stroke and prevent feed thereof, and means effective when said. saw is gripped to retract the saw without lifting it *from the saw cut.l

i2. In a safwing machine, a sau', a driving mechanism therefor', means fornorxnally exerting feed pressure on said saw, a member carried b v said saw, means for. gripping said member to prevent tbe feed of the saw, means whereby said gripping means is released on Ythe operative stroke of the saw, said means including a snriua; tensioning' plunger actuated `from the .saw driving J mechanism and disposed n gripping' tion to said men'iber, and manual means whereby said gripinng means may be initially released. v

13. In a sawing machine. a power shaft, a cam thereon, a saw driven from said`shait, means 'for enertil'ig .feed pressure on vsaid saw, a member carried by said saw, a` grip cluding a lever pivotaliy connected with said saw frame and actuated by the cani on said power shaft, and a spring controlled plunger carried by said lever and disposed.

and release mechanism Jfor said member ina grip and release mechanism for said mem.- ber including a lever pivotally connected with said saw traine and actuated by the cam on said power shaft, and a spring controlled plunger carried by said lever and disposed tor alternate engagement with and disengagement "from said member and manually operable release for said plunger.

15. in a sawing machine, a power shaft, a saw frame driven therefrom, a curved arm dependin from said saw frame, a lever actuated from said shaft, and a spring tensioucd device carried by said lever and having an exposed head rounded circumferentially to conform to the curvature oi said arm and i'iattened transversely of said arm and disposed for alternate grip and release of said arm.

lo. ln a sawing machine, a power shaft, a saw frame driven therefrom, a curved depenifling troni said saw frame, a lever actuated. from saidishait and having chamhered end, a spring tensioned plunger carried by said lever in said chamber and having an exposed head rounded circumieren tially to conform to the cur atnre of said arm and vflattened transversely or" said arm and disposed for alternate igrip and release o' said arm, and ia manually operable release device for said plunger.

1.7. in a sawing; machine, a power shaft, a saw ramedrivcn therefrom, a curved arm depending from said saw frame, a lever actuated from said shaft, a spring tensioned plunger carried by said lever and having an exposed head rounded circumfercntially to conform to the curvature of said arm and flattened transversely of said arm and disposed 'forengagement with said head and a manuallyv operable rele. se member having?, a flattened portion engageable with said first named member.

i8. in a sawing machine, a member to be v gripped a gripping.' clement releasably engaged therewith, and. a release device Vtor said clement including a reciprocable incur ber and a manuallyv operable element havinoA flattened area engageable with said rcciprocalne member to urge the saine against said gripping element.

il). in a sawing machine, a mernherto be gripped, a gripping element releasalilv engaged therewith, and a release device for said clement including a reciprocable stud and a manually operable actuating' pin hav ing; a, flattened area. eng; cable with said stud to u ,K the saine aganiat said gripping clement,

f. s sevrinr" machine, a saw frame, feed p tlfiere'tor, a. drive shai't,

drivin. ms hetwcen said shaft' and ming said ii .me to coi?, means whereby said gripping means is released on the operative stroke olf the. saw frame, a clutch mechanism for said drive shaft, a starting element having a portion for actuating' said clutch, means for supporting said element during the operation of the machine, and a release for said supporting means effective upon. completion of the cutting.

21. lin a sawing machine, a saw frame, gravity iced pressure means therefor, a drive shaft, driving connections between said shaft and frame, a member carried by the saw frame, means 'for automatically Lgripping said member to prevent feed of the saw frame, means whereby said gripping means is automatically released on the operative stroke ofthe saw frame, a clutch mechanism for said drive shaft, a starting lever having a member for actuating said clutch, means for supporting said lever during the operation of the machine, and a release :tor said supporting means effective upon completion of the cutting.'

Q2. in a sawing machine, a saw frame, gravity feed pressure means therefor, a drive shaft, driving connections bet-Ween said shaft and frame, means for gripping said frame to prevent thefeed thereof, means' .vhercby said gripping means is released on the operative stroke of the saw frame, a clutch'mechanism for said power shaft, a starting lever having a member for 'actuating saidclutch, means for supporting said lever during-the operation ot the machine, and an automatic release for said supporting means effective upon completion of the cnttin'. l

23. 1n a sawing machine, a power shaft, a member to be clutched rotating' therewith, a clutch member pivotally1 mounted and disposed for operative connection with said rotating member, a startling member having a clutch actuatingportion' yi'novalcle relative to said pivotally mounted clutch member, means normally tending to project said actuating portion toward said clutch member, and an automatic release device for said starting member eicctive upon completion 'of the sawing operation.

:24. In a sawing machinea power shaft, a member to be clutched rotating therewith, a clutch member pivotally mounted and disposed or operative connection with said rotating member, a starting' lever adapted to have a latched and an nnlatchcd position, a dog' thereon adapted to have a position out of the path of said pivotaily mounted clutch member and a position in the path oi said-member dependent upon the position ot said starting lever, means normally effective to project said dog into the path of said clutch member, a latch -for said starting lever. and an anien'mtic release for said latch effective upon completion of 'the sawing operation.

25. In a sawing machine, a power shaft, a ratchet thereon, a pawl pivotally mounted and disposed for operative connection with said ratchet, a. starting lever adapted to have a latched and an unlatched position, a dog thereon adapted to have a position out of the path of said pawl anda position in the path of said pawl, a spring engaging said starting lever and normally effective to project said dog into the path of said pawl,

a latch for said starting lever, andan automatic release for said latch effective upon completion of the sawing operation.

26. In a sawing machine, a power shaft, a ratchet thereon having a notch, a double ended pawl pivotally mounted betweenits ,ends with one end disposed for engagement in the notch of said ratchet, means normally urging said end into said notch and a start- V ing lever having a dog disposed for engagement with the opposite end of said pawl to rock said pawl upon its pivot.

27. In a sawing machine,1 a power shaft, a ratchet thereon having a notch, a double ended pawl pivotally mounted between its ends:

with one end disposed for engagement in the notch of said ratchet, a spring normally urging said end into said notch, a starting lever having a dog disposedffor engagementv trip device carried thereby, a power shaft,

a clutch therefor, a starting member adapted to have a latched and an unlatched position, a latch for said member for maintaining it in its latched position and actuatably disposed relative to said trip device, anda clutch shiftingl element operated by said starting element.

30. In a sawing machine` a saw frame, a trip device carried thereby', a power shaft, a clutchtherefor, a starting member adapted to have a'latched and an unlatched position, a latch consisting of a right angled member pivoted between its ends and having one end disposed for actuation by said trip device and the other end disposed for latchmg engagement with said starting member, and a clutch shifting device carried by said star"- ing member.

31. In a cutting machine, a power shaft, a

cuttingelement driven therefrom, a clutch part on said power shaft, a complementary clutch part movable into and out of engagingv relation to said first-named clutch part,

a shifting device normally maintaining said movable clutch part in non-engaging relation, an actuatingr mechanism for said shifting device to cause said device to release said movable clutch part, and automatic means acting on said movable clutch part for moving'it into engaging relation to said other clutch part upon actuation vof said shifting devic 32. In a cutting machine, a power shaft, a

cutting element driven therefrom, a clutch'l part on said power shaft, a complementary clutch part movable into and out of engag ing relation to said first-named clutch part, a shifting device for said movable clutch part, a 'spring acting on said device to cause said device to normally maintain said movable clutch part in non-engaging relation, an actuating mechanism for said shifting device to cause said device to release said movable clutch part, and a spring acting on said movable clutch' part for moving it into engaging relation to said other clutchpait upon actuation of said shifting device.

33. In a 'cutting machine, a power shaft,V

a cutting element, a clutch mechanism including a clutch part on the power shaft, a complementaryclutch part movable into and out of operative connecting relation to said lirst-named clutch part, a shifting mechanism' for said movable clutch part, and an automatic emergencyvstop adapted to act on a part of said'clutch shifting mechanism.

34. In a cutting machine, a power shaft, a cutting element, a clutch mechanism including a clutch part on the power shaft, a complementary clutch part movable into and out of operative connecting relation to said first-named clutch part, a shifting mechanism for said movable clutch part, and an automatic emergency stop comprising a pair of co-acting members carried, respectively,-l by one of the clutch 'parts and the clutch shifting mechanism.

35. In a cutting machine, a power shaft, a, part to be clutched 'rotating therewith, a clutch part movable into and out of operative connection with said rotating clutch part, and an actuatin'ginechanism for said complementary clutch part including a releasable member having'a portion normally maintaining said complementary clutch part in disengaged relation to said rotating clutch part. 1

36. In a cuttin machine, a power shaft, .a

part'to be clutc ed rotating therewith, a clutch part movable into.. and out of operative connection with saidA rotating clutch part, and an actuating mechanism foi; said complementary clutch part including' a "releasable member having a portion noipnaily n'iaint/aining Said. complementary clutch part in disengaged relation to Said rotating clutch part, means for releasing said member te cause said portion to release said complementary clutch part, and automatic means acting on said complementary dutch part to meme? move the same into eneaging position rela- 10 ife to the rotating clutch part upon i'eiease of said member.

n testimony7 whereof I affix my signature in pesenee of two Witnesses.

JOHN if?. BOYNTON. Witnesses Vim-oma LownnN,

GEORGE B. RMVMNGS. 

